Azo dyes



Patented Dec. 2, 1941 "AZO DYES Swanie S. Rossander, Wilmington, Del., William B. Reynolds, New York, N. Y., and Ghiles E. Sparks, Wilmington, iDeL, assignors to du Pont de Nemours & Company, Wilmington, Del., a corporation of Delaware No Drawing. Application September 6, 1939, Serial N0. 293,568

13 Claims.

This invention relates to azo dyes, to direct dyes, to dyes after-treated with formaldehyde and to metalized dyes.

Direct azo dyes are those which dye the cloth directly from a water bath without subsequent treatment to bring out the color. Many examples of such direct dyes are recorded in the literature. These direct colors are generally 'substantive to cotton and other forms of cellulose and regenerated cellulose, giving bright shades, and having moderate fastness to light. These colors, however, show considerable loss in strength and impart an undesirable stain to associated uncolored or differently colored fibers when they are washed. Direct colors with good washing fastness, and which will not stain associated fibers are in demand by the trade, because of their low cost and ease of application, but can be supplied but rarely. Because the direct azo dyes have poor fastness to washing the art has been forced to use the developed colors, wherein an intermediate, usually a direct dye,

isazotized on the fiber and developed with suitable coupling compounds. These so-called diazo colors or developed colors are generally faster to washing than the corresponding direct colors, but they are duller, more costly, more costly to apply as such dyeing operations require much labor and they change shade during development.

It'is an object of this invention 'to-provide a class of colors having the simplicity of application and constant, bright shade of the direct colors, and washing fastness superior to the direct colors. Another object of the 'inventionis to provide methods of applying the' colors, and of increasing their light fastness.

The objects of the invention are accomplished in general by applying to the material 'to'be'dyed, the direct tetrakisazo dyes represented by the formula and after treating the dyed fabric with formaldehye, formaldehyde and a soluble metalsalt or a soluble metal salt.

The symbol A in the foregoing formula is a meta-dihydroxy benzene represented by the'formula in which R is one of a group consisting of hydrogen, alkyl, alkoxy, aryl, aralkyl, hydroxy, amino, halogen, CN, carboxy and sulfonic acid.

The symbol X is a 'diamino-diphenylene compound in which the amino groups arein-meta or para position to the bridged carbons and are represented by the formula (B2) wherein the NHCO-groups are meta or'para to n is an integer 1 or 2, m is 2to 7, R1 is atleast one of a group consisting of hydrogen, alkyl, .alk'oxy, halogen, carboxyl'and sulfonic acid and where there is more than one B, the substituents may be alike or different, R2 is at'least-one of :a group consisting of hydrogen, alkyl, alkoxy, halogen, carboxy and sulfonic acid and where there is more than oneRz the substituents may be alike or difierent. When n is 1 in the general formula the symbol X stands :for a-diamino-diphenyl, such as benzidine or one of the indicatedderivatives thereof. 7

The-symbol Y .is a naphtholsulfonicacidderivative represented'by the formula NHONED R4 in WhiCh'Rs is'onelof a group consisting of hydrogen and 'sulfonic acid, one R4 is hydroxy'and'the other is hydrogen, one R5 is sulfonic acid'in a meta position to hydroxy andthe other is hydrogen, and R6 is one of a group consisting 'of sulfonic acid and carboxy.

In general the compounds may be made'by tetrazotizing one mol equivalent'of compound X and coupling in basic medium with two inol equivalents 'of the amino substituted amine of the naphthol sulfonic acid compound Y. This compound is isolated in any appropriate manner as by 'salting out and filtering. The product of this coupling Y X Y is then tetrazotized and. coupled in basic 'medium with two mol equivalents of a meta dihydroxy compound-A. The final product of coupling is A -Y -X Y' A- andis isolated'as by salting out and filtering.

The-dye'baths are'water solutions of these'produ ts'to which suitable dyeing assistants maybe added. Direct dyeings are made by entering the fabrics to be dyed in the dyebaths and then the dyeings are after-treated in a formaldehyde bath.

S OaNa The light fastness of these dyeings can be improved by additionally treating the dyeings with soluble metal salts.

The invention is more fully set forth in the following more detailed description which includes examples that are given as illustrative embodiments of the invention and not as limita tions thereof.

EXAMPLE I A slurry was made by adding 114 parts of 3-(4'-amino benzoyl amino) -l-amino benzene to 4,000 parts of water. The solids were dissolved by adding 91 parts of 100% hydrochloric acid as a 30% solution and heating to 3540 C. The solution was cooled to C. by adding ice and then tetrazotized by adding 69 parts of 100% sodium nitrite as a 30% solution. Tetrazotization was I carried out at 0-5 C. for one-half hour whilst maintaining a faint excess of nitrite. The soluble tetrazo was distinctly acid to Congo Red paper.

A slurry was made by adding 410 parts of 2- (4'-amino-3sulfophenyl amino) -8-naphthol- 6-sulfonic acid to 5,000 parts of water. The solids were dissolved by adding 200 parts of sodium carbonate and stirring. In this solution which was alkaline to Brilliant Yellow paper, 265 parts of sodium carbonate were dissolved and the solution was iced to 0 C.

The solution of the tetrazo was slowly added to the alkaline solution of 2-(4'-amino-3'-sulfophenyl amino) -8-naphthol-6-sulfonic acid whilst maintaining a temperature of 05 C. There was an excess of 2-(4'-amino-3'-sulfo-phenyl amino)-8-naphthol-6-sulfonic acid and the suspension was distinctly alkaline to Brilliant Yellow paper. The mixture was stirred one hour after all the tetrazo had been added and then heated to YO-80 C. The product of coupling was salted out with %-20% sodium chloride and filtered.

The filter cake was slurried with 4,000 parts of water, iced to 10 C. and 150 parts of 100% hydrochloric acid as a solution were added. 69 parts of 100% sodium nitrite as a 30% solution were slowly added and tetrazotization was carried out at.10-12 C. for one hour with a distinct excess of nitrite.

'A solution containing 132 parts of 1,3-dihydroxy benzene in 3,000 parts of water was iced to 0 C. and 300 parts of sodium carbonate were added to'the cooled solution.

The tetrazo was slowly added to the alkaline solution of 1,3-dihydroxy benzene. There was an excess of 1,3-dihydroxy benzene and the suspension was alkaline to Brilliant Yellow paper. The mixture was stirred for one hour after the addition of the tetrazo. The suspension was then heated to '70-80 C., salted slowly with 20% of sodium chloride and filtered. The filter cake was SOaNa SOQNa This dye gave a red chocolate dyeing on regenerated cellulose rayon.

In general, the dye may be dyed on the fiber and after-treated as follows: Dissolve 0.2 gram of the dye in 50 cc. water at 190-200 F., adding 0.4 g. of sodium carbonate to assist the solution. Dilute with stirring to a total volume of 500 cc. with water at approximately 160 F. Add 40 cc. of a 10% solution of Glaubers salt. Wet out a 10 gram piece of rayon with water, squeeze partially dry, and enter this into the dyebath. Raise the temperature of the dyebath to 180-190 F. in the course of fifteen minutes. Hold the dyebath at that temperature for one hour. Stir the dyeings at frequent intervals during this time. At the end of one hour remove the dyeing and rinse in cold water.

After-treatment in a fresh bath To 500 cc. of water at -l40 F. add the rinsed dyeing from the above operation. Then add approximately 10 cc. of 10% formaldehyde (25 cc. of approximately 37% formaldehyde by weight diluted to 250 cc. with water). Hold at this temperature for twenty minutes. Remove the dyeing, rinse and dry.

After-treatment in the dycbath An alternative after-treating process, which is the preferred procedure because of its economy and ease of application, is carried out as follows:

At the end of the dyeing period add to the dyebath 10 cc. of 10% formaldehyde as in the preceding example at bath temperature. Remove the dyeings after twenty minutes. Rinse and dry.

A dyeing with a red chocolate brown shade which showed excellent fastness to washing and good discharge properties was obtained with the dye of Example I.

EXAMPLE II A slurry was made by adding parts of 1,2-di-(4-amino-benzoyl-amino) -ethane to 4,000 parts of water. The solids were dissolved by adding 91 parts of hydrochloric acid as a 30% solution. The solution was cooled to 0-5 C. by adding ice and 69 parts of 100% sodium nitrite were added as a 30% solution. Tetrazotization was carried out at 0-5 C. for one-half hour with a slight excess of nitrite.

A slurry was made by adding 410 parts of 2 (4-amino-3-sulfo-phenyl-amino 8-naphthol- G-sulfonic acid to 5,000 parts of water. The solids were dissolved by adding 200 parts of sodium carbonate and stirring until complete solution was obtained. In this solution which was alkaline to Brilliant Yellow paper, 265 parts of sodium carbonate were dissolved with stirring and ice was added to cool the solution to 0 C.

The tetrazo was slowly added. to the alkaline solution and the mixture was stirred one hour. The resulting suspension was alkaline to Brilliant Yellow and there was present an excess of 2-(4'- amino-3' suliophenyl-amino) B-naphthol 6- sulfonic acid. The suspension was heated to70- 80 C. and salted with 15% sodium chloride.

The resulting filter cake was slurried with 4,000 parts of water and 150 parts of 100% hydrochloric acid were added as a 30% solution. The mixture was iced to 10 C; and 69 parts of 100% sodium nitrite were added as a 30% solution. Tetrazotization was carried out at 10-12 C. for one hour with a distinct excess of nitrite present.

A solution containing 132 parts of' 1.3-dihydroxy-benzene in 3,000parts of water was iced to C. and 300 parts of sodium carbonate were added.

The tetrazo was slowly added to the latter alkaline solution of 1,3-dihydroxy-benzene. There was an excess of 1,3-dihydroxy-benzene. The mixture was stirred for one hour after the addition of the tetrazo. The suspension was finally heated to 70-80 C., salted with 20% sodium chloride, filtered and dried at 80-85 C. The dry powder was deep brown in appearance.

The compound is represented by the formula some OH The product was dyed and after-treated in a manner analogous to that described in Example I. A dyeing with a yellow chocolatebrown shade S OzNa I n n IC some Nflois N- H H: 01 1 H; OH I was obtained which showed excellent fastness to washing.

EXAMPLE III A slurry was made by adding 140 parts of 2,2- dichloro 3,3'-dimethyl-4,4l-diamino-diphenyl to 4,000 parts of water. The slurry was treated with 91 parts of hydrochloric acid as a solution. The amino base was tetrazotized at 10-15 C. for about one hour with a slight excess of nitrite.

A slurry was made by adding 410 parts. of 2- (4 amino 3'-sulfo-phenyl-amino) 5-naphthol-7-sulfonic acid to 5,000 parts of water. A solution which was alkaline to Brilliant Yellow paper was made by adding 200 parts of sodium carbonate. The mixture was stirred to complete solution and 265 parts more of sodium carbonate were dissolved in the solution. This solution was iced to 0? C.

-The solution of the tetrazo was slowly added to thealkaline solution of 2-(4"-amino.-3'-sulfo'- phenyl amino.) 5 naphthol 7-sulfonic'acid whilst maintaining a temperature of 0 -5 C. There was an excess of the coupling component and the suspension was alkaline to Brilliant Yellow paper. The'mlxt'ure was stirred one hour after the addition of the tetrazo, heated to C., salted with 15% sodium chloride and filtered'.

The filter cake was slurried with 4,000 parts-oi water and 150 parts of 100% hydrochloric acid were added as a 30% solution. The solution was iced to 10 C. and 60 parts of 100% sodium nitrite were added as a 30% solution. Tetrazotization Was carried out at 10-12 C; for one hour with a distinct excess of nitrite.

A. solution was made by stirring 132 parts of 1,3-dihydroxy-benzene with 3,000 partsof water. The solution was iced to 0" C. and 300 parts of sodium carbonate were added.

The tetrazo was slowly added to the cold alkaline solution of 1,3-dihydroxy-benzene. There wasan excess of coupling compound and the suspension alkaline to Brilliant Yellow paper. The mixture was stirred one hour after the addition of the tetrazo, heated to '70-80 C. salted with 20% sodium chloride, filtered and dried at 80 S OaNa S OaN'B C. in an oven. The dry powder was black in appearance. The compound is represented by the formula HOGM SO;Na

The product was dyed and after-treated in a manner analogous .to that described in Example I. A dyeing. with a red violet shade was obtained which showed excellent fastness to Washing.

' EXAMPLE IV A slurry was made by adding 187 parts of 4,4- diamino-stilbene-2, 2-disulfonic acid to 4,000 parts of water. The solids were dissolved by adding 42 parts of sodium hydroxide and stirring. The solution which was slightly alkaline to Brilliant Yellow paper was iced to 0 C., 128 parts of hydrochloric acid were added andv the amino base was tetrazotized at 0-5 C. for onehalf hour with a distinct excess of nitrite.

A slurry was-made by adding 410 parts of 2'-(4'- amino-3-sulfo phenyl amino) 5 -naphthol-'T- sulfonic acidto 5,000parts of water. The solids were dissolved by adding 200 parts of sodium carbonate and stirring to complete solution. To the resulting solution which wasalkaline to- Brilliant Yellow paper, 285 parts of sodium carbonate were added and dissolved with stirring, and the solution was iced to C.

The solution of the tetrazo was slowly added to the alkaline solution of 2-(4-amino3'-sulfophenyl-amino)-5-naphthol-7-sulfonie acid and maintained at a temperature of 0-5 C. There was an excess of the coupling component and the suspension alkaline to Brilliant Yellow paper. The mixture was stirred one hour after the addition of the tetrazo, heated to '70-80 C., salted with 25% sodium chloride and filtered.

The filter cake was slurried with 4,000 parts of water, 150 parts of 100% hydrochloric acid were added as a 30% solution and the mixture was iced to C. The amino base was tetrazotized at 10-12 C. for one hour with a distinct excess nitrite by adding 69 parts of 100% sodium nitrite as a 30% solution.

A solution of 132 parts of 1,3-dihydroxy benzene in 3,000 parts of water was iced to 0 C., and 300 parts of sodium carbonate were added.

The tetrazo was slowly added to the cold alkaline solution of 1,3-dihydroxy-benzene. There was an excess of coupling component and the sus pension was alkaline to Brilliant Yellow paper. The mixture was stirred one hour after the addition of the tetrazo, heated to 70-80 C., salted with sodium chloride, filtered and dried at 80-85 C. in an oven. .The dry powder was black in appearance.

The compound is represented by the formula H N SOsNa H S OaNa N 5038 N N l The product was dyed and after-treated in a manner analogous to that described in Example I. A dyeing with a red blue shade was obtained which showed excellent fastness to washing.

EXAMPLE V A slurry was made by adding 114 parts of 3,3- diamino-azoxy benzene to 4,000 parts of water. The mixture was acidified by adding 91 parts of hydrochloric acid as a solution and the amino base was tetrazotized at 1015 C. for about one hour with a slight excess nitrite.

A slurry was made by adding 410 parts of 2- 4'-amino-3-sulfo-phenyl-arnino) 5 naphthol- 'l-sulfonic acid to 5,000 parts of water. A solu- CH=GHON=N- tion was made by adding 200 parts of sodium carbonate with stirring. The solution was alkaline to Brilliant Yellow paper and 265 parts more of sodium carbonate were added and dissolved. The solution was iced to 0 C.

The solution of the tetrazo was slowly added to the alkaline solution of 2-(4-amino-3'sulfophenyl-amino) -5-naphthol-7-sulfonic acid whilst maintaining a temperature of 05 C. There was an excess of the coupling component and the suspension was alkaline to Brilliant Yellow paper. The mixture was stirred one hour after the addition of the tetrazo, heated to 80 C., salted with 15% sodium chloride and filtered.

The filter cake was slurried with 4,000 parts of water, 150 parts of 100% hydrochloric acid were added as a 30% solution and the mixture was iced to 10 C. The amino base was tetrazotized at 10-12 C. for one hour with a distinct excess nitrite by adding 69 parts of 100% sodium nitrite as a 30% solution.

A solution was made by stirring 132 parts of 1,3-dihydroxy benzene with 3,000 parts of water. The solution was iced to 0 C. and 300 parts of sodium carbonate were added.

The tetrazo was slowly added to the cold alkaline solution of 1,3-dihydroxy benzene. There was an excess of coupling component and the suspension was alkaline to Brilliant Yellow paper. The mixture was stirred one hour after the addition of the tetrazo, heated to 70-80 C., salted with 20% sodium chloride, filtered and dried at NaOsS- N-- -85 C. in an oven. The dry powder was a deep brown in appearance.

The compound is represented by the formula SOaNB The product was dyed and after-treated as described in Example I. A dyeing with a maroon shade was obtained which showed excellent fastness to washing.

The following are additional illustrations of the invention. These products were prepared by methods similar to those recited in the foregoing examples. The most applicable variations in the method of making these compounds is apparent to those skilled in the art for any given example, wherever avariation is desirable. The direct dyeamino) -8-naphthol-6-sulfonic acid and 1(4'- amino-3-carboxy-phenyl-amino) -5-naphthol-7- sulfonic acid.

Y The compounds in which the Y components are the Z-(amino phenyl) amino derivatives of the naphthol mono-sulfonic acids are the preferred embodiments.

Deeper shades and better light fastness are produced by after-treatment of these colors with water-soluble metallic salts such as copper sulfate. This after-coppering operation may be carried out by either of the procedures outlined in Example I for the after-treatment with formaldehyde, by using a solution containing a 5% solution of hydrated cupric sulfate equal in amount to the formaldehyde.

The after-treatment with metal salts may be allowed to continue for twenty minutes or for such other time as is necessary to metallize the dyeing, at the end of which time the treated dyeings are removed, rinsed and dried. The aftercoppering may replace the formaldehyde treatment, but the use of both steps is preferred where improvement in light fastness is desired.

The double after-treatment may be done either in the dye bath or in a fresh bath. When a fresh formaldehyde bath is used and the dyeing is treated for a sufficient time to form the formaldehyde compound, the metal salt may be added and the treatment continued for another interval of time. The dyeings are then removed, rinsed and dried. Similar results are obtained by reversing the order of adding the reagents, that is by adding the solution of metal salt first, treating for the necessary time, say twenty minutes, and then adding the formaldehyde solution. After treating for about twenty minutes the dyeings are removed, rinsed and dried.

The described method of dyeing is typical but it is to be understood that the invention is not limited to the precise concentrations, temperatures and times of treatment specified since these details can be variously modified as will be understood by those skilled in the art. For example, the after-treatments with formaldehyde or metal salts may be carried on for longer or shorter periods and at higher or lower temperatures than those specified in the illustrations. Any treatment which will form a formaldehyde complex with the dyeing or a metal complex with the dyeing, as the case may be, produces the improved results. The exact composition of the described formaldehyde and metal complexes is unknown to us, but from our investigations it is our present belief that formaldehyde and metal complexes are formed.

Water-soluble salts of various metals can be used for metallizing the dyeings, those having atomic weights between 50 and 65 being the most suitable. As examples of such metals copper, chromium, nickel, cobalt and iron are mentioned. Either water-soluble salts of inorganic or organic acids can be used, such as sulfates, halides, formates and acetates, for example copper sulfate, nickel sulfate, chromium chloride, copper formate, copper acetate and many other watersoluble metal salts of inorganic and organic acids.

The invention provides bright dyeings having washing fastness equal to and in some cases superior to the diazo colors. The dyeings made in accordance with the invention are commonly produced more conveniently and more economically than the diazo colors since in a formaldehyde-treated direct dyeing only one bath is required, the dyeing operations are simple and very little change of shade is encountered; whereas in a diazo dyeing at least two baths are required, considerable change of shade is produced and the dyeing is a complicated procedure. The dyes may be made in the form of the acid salts of any of the alkali metals by using an appropriate base of the desired alkali metal for neutralization.

From the foregoing disclosure it will be recognized that the invention is susceptible of modification without departing from the spirit and scope thereof and it is to be understood that the invention is not restricted to the specific illustrations thereof herein set forth.

We claim:

1. The tetrakisazo compounds which in the form of their acids are represented by the formula in which X is the radical after azotization of a diamino-diphenylene compound represented by the formula NH: NH:

(B)n-|- I E I (B1) l)n in which E is one of a group consisting of NH- NH2 in which R3 is one of a group consisting of hydrogen and sulfonic acid, one R4 is hydroxy and the other is hydrogen, one R5 is sulfonic acid in a meta position to hydroxy and the other is hydrogen, and R0 is one of a group consisting of sulfonic acid and carboxy, and each A is the radical of a meta-dihydroxy benzene represented by the formula in which R is one of a group consisting of hydrogen, alkyl, alkoxy, aryl, aralkyl, hydroxy, amino, halogen, CN, carboxyl and sulfonic acid.

2. The tetrakisazo compounds which in the form of their acids are represented by the formula in which X is the radical after azotization of a apes-psi,

in?, which: 13; is. one of. a, group. consisting of;

diaminodiphenylene. compound represented. by thesformula;

NHz- NH:

in which B is one of a group consisting of CONH-, NHCONH--, NHCSNI-I,

n is an integer not greater than 2, m is an integer 2 to 7, R1 is from a group consisting of hydrogen, alkyl, alkoxy, halogen, carboxyl and sulfonic acid, R2 is from a group consisting of hydrogen, alkyl, alkoxy, halogen, carboxyl and sulfonic acid; Y is the radical after coupling and azotiza tion of a compound representedby the formula in which one R4 is hydroxy and the other is hydrogen, one R5 is sulfonic acid in a meta position to hydroxy and the other is hydrogen and Re is one of a group consisting of carboxyl and sulfonic acid; and each A is the radical of a metadihydroxy benzene represented by the formula in which R is one of a group consisting of hydrogen, alkyl, alkoxy, aryl, aralkyl, hydroxy, amino, halogen, CN, carboxyl and sulfonic acid.

3. The tetrakisazo compounds which in the form of their acids are represented by the formula HN- Rs 4 X Rs NH l w C 110G HzN- in which X is the radical after azotization of a diaminodiphenylene compound represented by the formula NH: NEE

rp U

n is an integer not greater than 2, m is an integer 2 to '7, R1 is from a group consisting of hydrogen,-,

alkyl, alkoxy, halogen, carboxyl and. sulfonic" acid, R2 is from a group consisting of hydrogen,

alkyl, alkoxy, halogen, carboxyl and sulfonic acid, one R4 is hydroxy and the other is hydrogen; one R5 is sulfonic acid and is meta to hydroxy and the other ishydrogen; and M is an alkali metal. 4. The compounds. represented by the formula CH3 7 V SOaX XOzS- NH in which X is an alkali metal.

5. The compound represented by the formula claim 5.

11. The metallic complexes of the compounds of claim 1.

12. The formaldehyde-metallic complexes of the compounds of claim 1.

13. The process of making a compound represented by the formula n is an integer not greater than 2, m is an integer 2 to 7, R1 is from a group consisting of hydrogen, alkyl, alkoxy, halogen, carboxyl and sulfonic acid, R2 is from a group consisting of hydrogen, alkyl,

alkoxy, halogen, carboxyi and suifonic acid; Y is the radical after coupling and azotization of a compound represented by the formula R5 I Ru in which R3 is one of a group consisting of hydrogen and sulfonic acid, one R4 is hydroxy and the other is hydrogen, one R5 is meta to a hydroxy group and is sulfonic acid and the other is hydrogen, and each A is the residue of a meta-dihydroxy benzene represented by the formula in which R is one of a group consisting of hydrogen, alkyl, alkoxy, aryl, aralkyl, hydroxy, amino, halogen, CN, carboxyl and sulfonic acid.

SWANIE S. ROSSANDER. WILLIAM B. REYNOLDS. CHILES E. SPARKS. 

